Microprocessor supervision in a special purpose computer system
First Claim
1. A special purpose computer system, comprising:
- a microprocessor having an operating system;
an internal watchdog timer internal to the microprocessor, the microprocessor toggling the internal watchdog timer and if the microprocessor does not toggle the internal watchdog timer for a first timer duration, the internal watchdog timer causes the microprocessor to reset;
an external watchdog timer external to the microprocessor, the microprocessor toggling the external watchdog timer and if the microprocessor does not toggle the external watchdog timer for a second timer duration, the external watchdog timer causes the microprocessor to reset; and
wherein the first timer duration is longer than the second timer duration.
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Accused Products
Abstract
Devices and methods for microprocessor supervision in a special purpose computer system are provided. One illustrative embodiment includes a first watchdog timer internal to the microprocessor and a second watchdog timer external to the microprocessor. In some cases, the internal watchdog timer may be initiated prior to or during the operating system startup and the external watchdog timer may be initiated after the operating system is up and running. The internal watchdog timer may have a relatively longer timer duration than the external watchdog timer, but is not required in all embodiments. In some embodiments, the internal watchdog timer may monitor the microprocessor'"'"'s startup sequence and the internal watchdog timer and/or external watchdog timer may monitor the microprocessor when the operating system is up and running. If the microprocessor faults at any time during startup or while the operating system is up and running, the internal and/or external watchdog timer may trigger a microprocessor reset.
24 Citations
20 Claims
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1. A special purpose computer system, comprising:
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a microprocessor having an operating system; an internal watchdog timer internal to the microprocessor, the microprocessor toggling the internal watchdog timer and if the microprocessor does not toggle the internal watchdog timer for a first timer duration, the internal watchdog timer causes the microprocessor to reset; an external watchdog timer external to the microprocessor, the microprocessor toggling the external watchdog timer and if the microprocessor does not toggle the external watchdog timer for a second timer duration, the external watchdog timer causes the microprocessor to reset; and wherein the first timer duration is longer than the second timer duration. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A special purpose computer system, comprising:
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a microprocessor including a commercial off-the-shelf operating system (COTS), a strobe output, and a reset input, wherein the reset input resets the microprocessor; an internal watchdog timer internal to microprocessor, the microprocessor toggling the internal watchdog timer and if the microprocessor does not toggle the internal watchdog timer for a first timer duration, the internal watchdog timer causes the microprocessor to reset; an external watchdog timer including a strobe input coupled to the strobe output of the microprocessor, a reset output coupled to the reset input of the microprocessor, and a timer having a second timer duration, wherein the microprocessor toggles the external watchdog timer and if the microprocessor does not toggle the external watchdog timer for a period that is greater than or equal to the second timer duration, the external watchdog timer asserts the reset output causing the microprocessor to reset; and wherein the first timer duration is different than the second timer duration. - View Dependent Claims (12, 13, 14, 15, 16)
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17. A method for supervising a microprocessor of a special purpose computer system, comprising:
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launching an operating system of the microprocessor, the operating system taking an operating system launch time to fully launch and achieve normal operation; enabling a first watchdog timer prior to or during the launching step, the first watchdog timer having a first timer duration that causes the first watchdog timer to expire after the operating system launch time, the microprocessor toggling the first watchdog timer and if the microprocessor does not toggle the first watchdog timer prior to the expiration of the first timer duration, the first watchdog timer causing a microprocessor reset; enabling a second watchdog timer after the launching step, the second watchdog timer having a second timer duration that is shorter than the first timer duration, the microprocessor toggling the second watchdog timer and if the microprocessor does not toggle the second watchdog timer prior to the expiration of the second timer duration, the second watchdog timer causing a microprocessor reset; and causing a microprocessor reset if the first watchdog timer or the second watchdog timer expires. - View Dependent Claims (18, 19, 20)
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Specification